Electrically-heated vessel.



W. B. UNDERWOODL ELECTRI CA LLY HEATED VESSEL.

APPLICATION FILED DEC-14.1915

1,192,477. Patented July 25, 1916.

UNITED STATES PATENT OFFICE.

WEEDEN B. UNDEBWOOD, OF ROCHESTER, NEW YORII, ASSIGNOR TO WILMOT CASTLECOMPANY, OF ROCHESTER, NEW YORK. A CORPORATION.

ELECTBICALLY-HEATED VESSEL.

Specification of Letters Patent.

Patented July 25, 1916.

Application filed December 14, 1915. Serial No, 66,822.

T 0 all whom it may concern:

Be it known that I, WEEDEN B. UNDER- -woo1), a citizen of the UnitedStates, and

This invention relates to vessels in which 7 water or other fluids areheated by electrical means, and particularly to vessels used assterilizers for surgical instruments. In vessels of the kind in questionit has been common to employ automatic means for breaking the electriccircuit, by which the heatingelements are energized, upon the attainmentof a dangerous temperature, such as might occur in case the water isallowed to evaporate entirely from the vessel.

This invention relates particularly to such automatic devices, and oneobject of the invention is to produce an arrangement in which a fusiblemember is employed, for the purpose in question, in a novel and simplemanner, havingparticular regard to accessibility and convenient renewalof the fusible member, and to the use of a member of simple andinexpensive form.

Another object of the invention is to provide f'r inclosing thecircuit-breaker and all otliier parts of the automatic device inquestiop, except that part which is necessarily accessible for thepurpose of renewing the fusible member.

Other objects of the invention, and the features of construction bywhich the various objects are attained, will be set forth hereinafter,in connection with the following description of the illustratedembodiment of the invention.

In the accompanying drawings: Figure 1 is a front-elevation of awaterboiler or sterilizer embodying the present invention, shown partlyin vertical section; Fig. 2 is a bottom-view of a part of thesterilizer, with the bottom of the casing removed; Fig. 3 is a plan-viewof a part of the sterilizer, with the cover removed; and Fig. 4 isavertical sectional view, on a larger scale than the preceding figures,showing the automatic heatcontrolled circuit-breaker in open-circuitposition.

Theinvention is illustrated as embodied in a'sterilizer having a vesselor body which comprises side-walls 5, a flat bottom 6, and a removablecover 7.

The receptacle is heated by a plurality of flat, elongated, electricheating-units 8, of anyordinary or suitable form, whichlie directlyagainst the lower surface of the bottom 6. The heating-units are held inplace by. means of a plate 9 beneath them, and screws 10 are passedthrough openings in the plate and in the bottom 6, and are threaded intoa rigid metal frame 11, which lies on the upper surface of the bottom 6.

The frame 11, in addition to constituting a part of the means forclamping the heating-units against the bottom 6, acts also to divide thespace immediately above the bottom 6 so as to provide pockets 12. Sincethese pockets lie directly above that part of the bottom which is incontact with the heating-units, if the user fails to replenish the waterin the sterilizer, that part of the water which is in these pockets willbe first evaporated, so that the pockets become dry while there is stillenough water remaining in the exterior space to prevent injury to thesoldered joint between the bottom 6 and the side-walls 5. Thetemperature of that part of the bottom within the pockets will rise,however, at this time above the boiling-point of the water, andadvantage is taken of this fact to automatically break the electric circult and interrupt the action of the heatingunits before the water isentirely exhausted from the sterilizer. For the foregoing purpose acircuitbreaker is employed comprising fixed contact-springs-13 andpivotally mounted contact-springs 14c. The springs 13 are mounted on,but insulated from, a bracket 15 fixed to and depending from the plate9, and the springs are connected to bindingposts 16 by which they may beconnected, in turn, with one terminal of a source of electric current.The contact-springs 14 are mounted on, but insulated from, a bar 17which has pivots 18 formed at its ends, and these pivots engage holes inbrackets 19 fixed to. and depending from the plate 9. Eachcontact-spring 14 is connected by a flexible conductor 20 with oneterminal of one of the heating-units 8, the other terminals of the unitbeing connected, by a connector 21, with a binding-post 22 through whichconnections maybe made with the external source of current.

The heat-controlled device comprises a hollow post 23, of which theupper end is fixed in the bottom 6 by means of a cap-nut 24. A plunger25 is arranged to slide within the post, and a compression-spring 26,inclosed within the post, bears downwardly on this plunger. The fusiblemember is in the form of a shearing-pin 27, which engages perforationsin the post and plunger and normally retains them in the position shownin Fig. l.

The post and the plunger are longitudinally slotted, to receive a flatarm 2-8 which extends from the bar 17. This arm, in turn, is slotted toreceive a pin 29 which passes transversely through the upper end of theplunger. In the upward position of the plunger the parts are held sothat the contact-springs are in engagement. When the bottom 6 becomesoverheated, however, the heat is conducted down the post to theshearing-pin, and when the predetermined temperature is reached this pinis melted, whereupon the spring 26, assisted by the force of gravity,moves the plunger and the. arm 28 downwardly, thus separating thecontactsprings, as shown in Fig. 4, and breaking the circuit through theheating-units.

It is desirable to have the electrical devices inclosed safe from dust,or from interference or injury, while at the same time having thefusible member conveniently accessible for replacement when necessary.The arrangement above described lends it self conveniently to suchinclosure. As shown in the drawings, the sides 5 and the bottom of thebody of the vessel are extended downwardly to form the sides 30 of acasing, and this casing is closed at the bottom by a plate 31. The postand the plunger extend downwardly through an opening in the plate 31, sothat they are always accessible for the purpose of resetting thecircuitbreaker, but all of the other parts of the circuit-controllingmechanism are inclosed within the casing. The vessel is supported uponlegs 32, so as to raise the post and the forms within the nature of theinvention as it is defined in the following claims.

I claim l. The combination, with a heating-unit, of a circuit-breakerconnected therewith, and means for controlling the latter, comprising ahollow post adapted to engage the heated body, a plunger slidable in thepost, and connected with the circuit-breaker, and a fusible shear-pinnormally connecting the plunger and the post and preventing relativemovement thereof.

2. A circuit-breaker comprising a hollow post adapted to engage a heatedbody, a plunger slidable in the post, and connected with-thecircuit-breaker, and a fusible shearpin normally connecting the plungerand the post, preventing relative movement thereof and adapted toreceive heat from the heated body through the hollow post.

3. In anelectrically-heated vessel, the combination, with the body ofthe vessel, and a heating-unit attached thereto, of a circuit-breakerconnected with the heatingunit; and means, for'controlling thecircuitbreaker, comprising a hollow post engaging the body of thevessel, a plunger slidable in the post, and connected with thecircuitbreaker, and a fusible shear-pin normally connecting the plungerand the post and preventing relative movement thereof.

4. In an electrically-heated vessel, a cirmember and a pivotedcontact-niember;' a hollow post adapted for connection, at one end, withthe heated body of the vessel; a plunger movable in the post; a springin closed in the post and engaging the plunger; 9. fusible shear-pinconnecting the post and the plunger and normally preventingmovecuit-breaker comprising a fixed contactment of the latter; andpin-and-slot connece tions between the plunger and the pivotedcontact-member.

.WEEDEN B. UNDERWOOT).

